Hi,
this might be of interest to you. I have added PXE network driver support for my GRUB patch set recently. This enables GRUB to load files via the network using any PXE capable NIC, including latest e1000, Broadcom, e100, 3coms, etc. cards. The patch, README and binary are at the usual place at:
http://os.inf.tu-dresden.de/~adam/grub/0.97/
Refer to the README file for details.
If you have a NIC that has PXE and does not work, please let me know.
Adam